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Soyuz launch vehicle
The Soyuz launch vehicle (Western designation: A-2) is an expendable launch system designed by the Korolev Design Bureau (Soviet Union) and used as the launcher for the manned Soyuz spacecraft, as part of the Soyuz program. However it is a general purpose launch vehicle with other uses, including launches of the Progress cargo spacecraft and commercial launches marketed and operated by TSeEsKAbe and the Starsem company. There were 11 Soyuz launches in and 9 in . Soyuz vehicles are launched from the Baikonur Cosmodrome in Kazakhstan and the Plesetsk Cosmodrome in northwest Russia. They are manufactured in Samara, Russia. History The launcher was introduced in , deriving from the Vostok launcher, which in turn was based on the 8K74 or R-7a intercontinental ballistic missile. It was initially a three-stage rocket with a Block I upper stage. Later a Molniya variant was produced by adding a fourth stage, allowing it to reach highly elliptical orbits. A later variant was the Soyuz-U. The production of Soyuz launchers reached a peak of 60 per year in the early 1980s. It has become the world's most used space launcher, flying over 850 times, far more than any other rocket. It is a very old basic design, but is notable for low cost and very high reliability, both of which appeal to commercial clients. In the early plans were made for a redesigned Soyuz with a Fregat upper stage. The Fregat engine was developed by NPO Lavochkin from the propulsion module of its Phobos interplanetary probes. Although endorsed by the Russian Space Agency and the Russian Ministry of Defence in 1993 and designated "Rus" as a Russification and modernisation of Soyuz, and later renamed Soyuz 2, a funding shortage prevented implementation of the plan. The creation of Starsem in July provided new funding for the creation of a less ambitious variant, the Soyuz-Fregat or Soyuz U/Fregat. This consisted of a slightly modified Soyuz U combined with the Fregat upper stage, with a capacity of up to 1,350 kg to geostationary transfer orbit. In April , Starsem obtained a contract from the European Space Agency to launch two pairs of Cluster 2 plasma science satellites using the Soyuz-Fregat. Before the introduction of this new model, Starsem launched 24 satellites of the Globalstar constellation in 6 launches with a restartable Ikar upper stage, between , and , 1999. After successful test flights of Soyuz-Fregat on , and , 2000, the Cluster 2 satellites were launched on , 2000 and , 2000. Another Soyuz-Fregat launched the ESA's Mars Express probe from Baikonur in June . Now the Soyuz-Fregat launcher is used by Starsem for commercial payloads. It is due to be replaced by the new launcher, now named Soyuz/ST (or Soyuz-2), which will have a new digital guidance system and a strongly modified third stage with a new engine. The first development version of Soyuz-2 called Soyuz-2-1a, which is already equipped with the digital guidance system and a modified third stage, but is still propelled by an old engine, started on , from Plesetsk on a suborbital test flight. The fully modified launcher (version Soyuz-2-1b) is planned to fly<--! obviously this needs to be updated - 2006 is hardly the future! --> first in the spring of from the Baikonur Cosmodrome. A long string of successful Soyuz launches was broken on , when the unmanned Soyuz U launch of the Photon-M satellite from Plesetsk exploded 29 seconds after lift-off. One person was killed and eight injured. Another failure occurred on , , during a Molniya military communications satellite launch from the Plesetsk launch site, which used a four-stage version of the Soyuz rocket called Molniya-M. The flight ended six minutes after the launch because of a failure of the third stage engine or an unfulfilled order to separate the second and third stages. The rocket's second and third stages, which are identical to the Soyuz, and its payload (a Molniya-3K satellite) crashed in the Uvatski region of Tyumen (Siberia) http://en.rian.ru/russia/20050621/40556511.html. However, under this designation of Molniya-M launcher, other 274 unmanned Soyuz launches have been successful. Soyuz (in the new version Soyuz/ST) is also planned to be brought into ESA service in <--! obviously this needs to be updated - 2007 is hardly the future! -->under a Russo-European joint venture. It is planned to build a new launch pad in French Guiana. Stages First stage The first stage of Soyuz rockets consists of four identical conical liquid booster rockets, strapped to the second stage core. Each booster has a single rocket motor (four combustion chambers, two vernier combustion chambers, one set of turbopumps). Statistics (each of 4 boosters) * 44.5 metric ton gross mass * 39.2 metric ton propellant * 3,784 kg dry mass * 2.68 meter diameter (8.8 feet) * 19.6 meter length (64.3 feet) * Engines: ** Soyuz and Soyuz-U models *** RD-107 **** Thrust 813 kN (182 klb) at liftoff **** Thrust 991 kN (223 klb) in vacuum **** Specific impulse 245 seconds at liftoff **** Specific impulse 310 seconds in vacuum **** Chamber pressure 58.5 bar (848 psi) ** Soyuz-ST models *** RD-117 **** Thrust 838 kN (188 klb) at liftoff **** Thrust 1021 kN (229 klb) in vacuum **** Specific impulse 245 seconds at liftoff (est) **** Specific impulse 310 seconds in vacuum (est) **** Chamber pressure 58.5 bar (848 psi) Second stage The second stage of the Soyuz booster is a single, generally cylindrical stage with one motor (four combustion chambers, four vernier combustion chambers, one set of turbopumps) at the base. The stage gets somewhat wider near the top. * 105.4 metric ton gross mass * 95.4 metric ton propellant (210,000 lb) * 96.4 metric ton propellant Soyuz-U2 with Syntin propellant (212,000 lb) * 6,875 kg dry mass * 28 meters long * 2.95 meters diameter * Engines: ** Soyuz and Soyuz-U models *** RD-108 **** Thrust 779 kN (175 klb) at liftoff **** Thrust 997 kN (224 klb) in vacuum **** Specific impulse 264 seconds at liftoff **** Specific impulse 311 seconds in vacuum **** Chamber pressure 51 bar (740 psi) ** Soyuz-U2 model with Syntin fuel *** RD-108 **** Thrust 811 kN (182 klb) at liftoff **** Thrust 1009 kN (227 klb) in vacuum **** Specific impulse 264 seconds at liftoff **** Specific impulse 311 seconds in vacuum **** Chamber pressure 51 bar (740 psi) ** Soyuz-ST models *** RD-118 **** Thrust 792 kN (178 klb) at liftoff **** Thrust 990 kN (222 klb) in vacuum **** Specific impulse 264 seconds at liftoff (est) **** Specific impulse 311 seconds in vacuum (est) **** Chamber pressure 58.5 bar (848 psi) Third stage There are two variant upper stages in use, the Block I and Improved Block-I (used in Soyuz-2-1b). * 25.2 metric ton gross mass * 21.4-22.9 metric tons propellant * 2355 kg dry mass * 6.7 meters long (22.0 feet) * 2.66 meters diameter (8.73 feet) * Engine: ** Block I *** RD-0110 *** Thrust 298 kN (67 klb) *** Specific impulse 330 sec *** Chamber pressure 68 bar (986 psi) ** Improved Block I *** RD-0124 *** Thrust 294 kN (66 klb) *** Specific impulse 359 sec *** Chamber pressure 162 bar (2350 psi) External links * R-7 missile family page * Starsem * Soyuz launch log at Starsem * Soyuz U/Fregat References * International Reference Guide to Space Launch Systems, Third Edition, Iaskowitz, Hopkins, and Hopkins ed., 1999, Reston, Virginia, AIAA Publications. ISBN 1-56347-353-4 Category:Spacecraft